Split architectures for MEA durability

Abstract

A membrane electrode assembly including an ionically conductive member, an electrode, and an electrically conductive member including an active layer, wherein the electrode is a smooth, continuous layer that completely covers and supports the ionically conductive member. The electrode and active layer further include a first and second catalyst content, respectively; and 50% of the total catalyst content is present in the electrode and 50% of the total catalyst content is present in the active layer.

1. An assembly for a fuel cell comprising:
 an ionically conductive membrane having a major surface; 
 an electrically conductive member facing said membrane major surface and having an active layer, said active layer having an active layer catalyst content; and 
 an electrode between said ionically conductive membrane and said electrically conductive member, said electrode having a major surface at said membrane major surface, and said electrode having an electrode catalyst content, 
 wherein said electrode has a peripheral extent substantially the same as the membrane and wherein said electrode further comprises a central region and a peripheral region, said central region having a first group of catalyzed particles dispersed in a binder, said peripheral region having a second group of particles dispersed in a binder that are catalyzed or uncatalyzed, said peripheral region overlapping a peripheral extent of said active layer, and said central region being within said peripheral extent of said active layer; 
 wherein said peripheral region is electrically non-conductive. 
 
     
     
       2. An assembly for a fuel cell comprising:
 an ionically conductive membrane having a major surface; 
 an electrically conductive member facing said membrane major surface and having an active layer, said active layer having an active layer catalyst content; and 
 an electrode between said ionically conductive membrane and said electrically conductive member, said electrode having a major surface at said membrane major surface, and said electrode having an electrode catalyst content, 
 wherein said electrode has a peripheral extent substantially the same as the membrane and wherein said electrode further comprises a central region and a peripheral region, said central region having a first group of catalyzed particles dispersed in a binder, said peripheral region having a second group of particles dispersed in a binder that are catalyzed or uncatalyzed, said peripheral region overlapping a peripheral extent of said active layer, and said central region being within said peripheral extent of said active layer; 
 wherein the first group of particles is dispersed in an ionically conductive binder, and said second group of particles is dispersed in an ionically non-conductive binder. 
 
     
     
       3. A membrane electrode assembly comprising:
 an ionically conductive membrane having a major surface; 
 an electrode at said major surface, said electrode defining a continuous layer supporting said membrane; and 
 an electrically conductive member adjacent said electrode and including an active layer; 
 wherein at least one of said electrode and said active layer comprise a central region and a peripheral region; 
 a gradient of electrochemically active material exists between said central region and said peripheral region such that a content of said electrochemically active material is greater in said central region than said peripheral region, 
 wherein said peripheral region is separate and distinct from a sealing member. 
 
     
     
       4. The membrane electrode assembly according to  claim 3 , wherein said central region includes a first group of particles that are electrically conductive, and said peripheral region includes a second group of particles that are electrically non-conductive. 
     
     
       5. The membrane electrode assembly according to  claim 3 , wherein said electrode provides structural support to said membrane and thereby restricts movement of said membrane. 
     
     
       6. The assembly according to  claim 3 , wherein said central region comprises an ionically conductive binder retaining electrically conductive particles and an active material. 
     
     
       7. The assembly according to  claim 3 , wherein said peripheral region comprises an ionically non-conductive binder retaining said electrically non-conductive particles and said active material. 
     
     
       8. The assembly according to  claim 3 , wherein said peripheral region further comprises thermally conductive material. 
     
     
       9. The assembly according to  claim 7 , wherein said ionically non-conductive binder is a thermoplastic resin. 
     
     
       10. The assembly according to  claim 3 , wherein said electrode and said active layer further comprise a first catalyst content and a second catalyst content, respectively; and
 said first catalyst content includes 50% of the total catalyst content of the assembly, and said second catalyst content includes 50% of the total catalyst content of the assembly. 
 
     
     
       11. The assembly according to  claim 3 , wherein said electrically conductive member further comprises an intermediate layer comprising carbon particles dispersed in a binder that couples said active layer and said electrically conductive member. 
     
     
       12. The assembly according to  claim 11 , wherein said intermediate layer is a water management layer.